The present invention relates to the field of doors. More specifically, the present invention relates to an astragal system for swinging-type hinged doors.
A double door system includes a pair of hinged swinging-type doors, one of which is typically the active door and the other of which is typically the inactive door. An active door is the door that opens first and is the one to which the latch is applied. An inactive door is the door that is bolted when closed and to which the lock strike is fastened to receive the latch of the active door.
Due to the clearances needed and the geometry of swing of a pair of doors, a gap generally occurs between the pair of doors at their meeting edges when the two doors are completely closed. This clearance gap is typically between one quarter and three eighths of an inch wide. Accordingly, double doors can include an astragal closing this clearance gap for the purpose of either providing a weather seal, minimizing the passage of light between the doors, or retarding the passage of smoke or flame during a fire.
Some prior art astragals overlap the clearance gap. For example, an astragal may be attached to the active door and extend laterally from the edge of the door to overlap the gap. Other astragals meet at the centerline of the gap (sometimes referred to as a split astragal).
Door closing coordinators are well known in the art and serve the function of controlling the sequence in which the inactive and active doors close. Door closing coordinators are commonly used in conjunction with doors that have some type of automatic door closing mechanism that will move a door from an open to a closed position after the door has been released. The coordinators ensure that the inactive door reaches a fully closed position before the active door regardless of the relative positions the doors are in when they are released, the speed with which each door closes, or other variables. Coordinators are necessary when an overlapping astragal is present so that the door fitted with the astragal closes last, thereby allowing the pair of doors to close properly.
While a variety of coordinators are known, many have certain shortcomings. Some coordinators are mounted on the door headers in a completely exposed location. Such coordinators are unsightly. More recent coordinators are fabricated to be mounted under the header door stop. These designs are far superior in appearance to the exposed coordinators. Unfortunately, however, these coordinators require frequent maintenance and adjustment. Due to wear on the coordinators, adjustment is particularly critical with a very active entry. The excessive wear causes the coordinators to readily fall out of adjustment, resulting in the hazardous situation in which the doors fail to close and latch properly every time.
A fire door assembly is any combination of a fire door (single or double doors), a frame, hardware, and other accessories that together provide a specific degree of fire protection to the opening, while at the same time allowing building occupants to pass through.
The National Fire Protection Association (NFPA) is an international organization that provides and advocates scientifically-based consensus codes and standards, research, training, and education. The NFPA 80 is the standard for fire doors and fire windows. NFPA 80 covers the installation and maintenance of fire door assemblies, windows, glass blocks, and shutters for the protection of openings to restrict the spread of fire and smoke within buildings, whether from interior fire or from external fire, including arrangements for automatic operation in case of fire.
Regarding the operation of fire doors, NFPA 80 specifies that all swinging doors shall be closed and latched at the time of fire and shall close and latch thereafter each time it is opened. The NFPA 80 further specifies that doors swinging in pairs and having a fire protection rating of more than one and a half hours shall have an overlapping astragal. In addition, pairs of doors that require astragals shall have at least one attached in place so as to protect approximately three quarters of an inch.
Inappropriately configured astragals and/or coordinators that fail to allow a pair of doors to close and latch properly can be irritating to individuals passing through the doors under normal use conditions. More critically, the failure of a pair of doors to close and latch properly in case of an interior or external fire can create an extremely hazardous situation in which the spread of fire and/or smoke is unrestricted. Thus, what is needed is an astragal system for a door that enables unrestricted opening and closing of doors under normal conditions, while restricting the spread of fire and smoke in the case of a fire.
Accordingly, it is an advantage of the present invention that an automatically extendable astragal system is provided.
It is another advantage of the present invention that an astragal system is provided that enables the free movement of either door in a double door assembly under normal use conditions.
Another advantage of the present invention is that an astragal system is provided with an overlapping configuration that meets NFPA standards for fire doors.
Yet another advantage of the present invention is that an astragal system is provided that precludes the need for door coordinators.
The above and other advantages of the present invention are carried out in one form by an extendable astragal system for a door. The astragal system includes a housing, an actuating member located in the housing and slidably engaged with the housing, and an astragal located in the housing and slidably engaged with each of the housing and the actuating member. The astragal system further includes a latch mechanism retaining the astragal within the housing in a retracted position when an ambient temperature is below a predetermined temperature. The latch mechanism enables sliding movement of the actuating member and resultant movement of the astragal to an extended position outside of the housing when the ambient temperature is at the predetermined temperature.